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BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath

write to 0xffffc900015efae8 of 1 bytes by task 6754 on cpu 1:
 rwsem_try_write_lock kernel/locking/rwsem.c:676 [inline]
 rwsem_down_write_slowpath+0x3eb/0xab0 kernel/locking/rwsem.c:1189
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xad/0xc0 kernel/locking/rwsem.c:1632
 kernfs_add_one+0x5a/0x350 fs/kernfs/dir.c:825
 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1079
 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:316
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x43e/0x9e0 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:255
 setup_port drivers/infiniband/core/sysfs.c:1202 [inline]
 ib_setup_port_attrs+0xa2c/0x1480 drivers/infiniband/core/sysfs.c:1388
 add_one_compat_dev+0x297/0x390 drivers/infiniband/core/device.c:1002
 rdma_dev_init_net+0x1b9/0x240 drivers/infiniband/core/device.c:1227
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:137
 setup_net+0x9f/0x230 net/core/net_namespace.c:443
 copy_net_ns+0x333/0x490 net/core/net_namespace.c:582
 create_new_namespaces+0x1f6/0x420 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x115/0x150 kernel/nsproxy.c:234
 ksys_unshare+0x42b/0x710 kernel/fork.c:3292
 __do_sys_unshare kernel/fork.c:3356 [inline]
 __se_sys_unshare kernel/fork.c:3354 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3354
 x64_sys_call+0x1e33/0x2550 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc900015efae8 of 1 bytes by task 364 on cpu 0:
 rwsem_down_write_slowpath+0x462/0xab0 kernel/locking/rwsem.c:1207
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xad/0xc0 kernel/locking/rwsem.c:1632
 kernfs_remove_by_name_ns+0x6b/0x110 fs/kernfs/dir.c:1792
 kernfs_remove_by_name include/linux/kernfs.h:644 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xa5/0x170 fs/sysfs/group.c:328
 sysfs_remove_groups+0x3a/0x80 fs/sysfs/group.c:352
 destroy_gid_attrs drivers/infiniband/core/sysfs.c:1138 [inline]
 ib_free_port_attrs+0x8e/0x250 drivers/infiniband/core/sysfs.c:1362
 remove_one_compat_dev drivers/infiniband/core/device.c:1035 [inline]
 rdma_dev_exit_net+0x1aa/0x330 drivers/infiniband/core/device.c:1173
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x285/0x420 net/core/net_namespace.c:253
 cleanup_net+0x37c/0x5b0 net/core/net_namespace.c:706
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3479
 worker_thread+0x569/0x750 kernel/workqueue.c:3560
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 364 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
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